I usually do not like cheating but this time I didn't mind I don't know why. I am weird. ...

I think it's because we don't really know "Megane-san" yet; if he'd had more "screentime", I think I'd have felt a lot more disturbed by the uke cheating on him, however, it just seems like the uke's feelings for his ex have been reignited - as if they were never gone. Usually, it's impossible for me to read a manga where one of the main characters is cheating on their love interest. Megane-san doesn't feel like a real character yet because we've barely heard him speak yet. Let's hope he hasn't fallen too deeply in love with the uke (￣∇￣") I have a feeling (or, lol, I know) he's about to get dumped in a few chapters...